Differential mounted single stage diaphragm operated pump

ABSTRACT

An air compressor having a diaphragm-piston connected to a cam operated push rod for producing a single stage compression of air through a wide range of desired static pressures in accordance with the position of an open ended housing in a support fixture which positions the push rod with respect to the high point of a cam operator to maintain a predetermined clearance volume within the pumping chamber of the compressor. Clearance volume is held by means of a clamp device for fixedly securing the axially adjusted compressor housing with respect to the cam operator.

United SKaEQS atent 1 1 Schlanzlry Oct. 15, 1974 [54] DIFFERENTIALMOUNTED SINGLE STAGE 3,151,568 10/1964 Hood et al .1 92/100 DIAPHRAGMOPERATED PUMP 3,168,855 2/1965 Randol 92/100 3,199,458 8/1965 Hochn417/311 [75] Inventor: Manfre P- H- hl n ky, 3,252,424 5/1966 Johnson eta1 417/471 Frankenmuth, Mich. 3,375,972 4/1968 Ruuceisen r 92/605 [73]Assigneez G e Mo s po tio 3,650,182 3/1972 Phillips 92/165 Detrolt Mlch'Primary ExaminerWilliam L. Freeh [22] Filed: Nov. 16, 1972 AssistantExaminer-Gregory P. LaPointe [21] pp No: 307,331 Attorney, Agent, orFzrm-Charles R. White [57] ABSTRACT C 417/274 92/ An air compressorhaving a diaphragm-piston con- 58 d 1 472 311 nected' to a cam operatedpushv rod for producing a 1 g 21 13 7 531 100 60 f 123748 5 single stagecompression of air through a wide range of desired static pressures inaccordance with the position of an open ended housing in a supportfixture [56] References'clted which positions the pushrod with respectto thehigh UNlTED STATES AT point of a cam operator to maintain apredetermined 862,867 8/1907 E leston 417/395 clearance volume withinthe pumping-chamber of the 1,896,098 2/1933 Foyer 123/48 compressor.Clearance volume is held by means of a Knudsen C clamp device forfixedly ecuring the axially adjusted 2956738 10/1960 92/605 compressorhousing with respect to the cam operator. 3,035,676 5/1962 Nallinger r417/470 I 3,095,824 7/1963 Elfes 417/471 4 Claims, 5 Drawing Figures a65 10 62 :20 15a 3 1 411 87 M 54 15s 53 w a2 72 50 I40 I28 126 151 2117b6! w 52 {as so t i DIFFERENTIAL MOUNTED SINGLE STAGE DIAPHRAGMQPERATEDPUMP This invention relates to air compressor and more particularly toair compressors of the type including a dry-diaphragm-piston which isoperated through a short stroke to produce a single stage compression offluid.

Compressed air systems used on vehicles include cam operated singlestage dry diaphragm-piston compressorsproducing high volume dischargeofcompressed air for use in the systems. The advantage of sucharrangements is that the diaphragm pistoncombination has desirable lifecharacteristics and eliminates the need for lubricating frictionsurfaces of the type found between piston and cylinder compressor units.

Atypical diaphragm piston cam operated single stage compressor has afixed volumetric capaeitythat only can bevaried by changing the volumeof a pumping chamber within the device.

Certain of single stage compressors-have an oil chamber on one sidethereof through which oil is circulated to produce a pumping action onthe diaphragm piston.

The present invention is directed to a compact, shortstrokediaphragm-piston air compressor that is cam operated to produce a singlestage compression of fluid wherein the diaphragm pistonis operatedwithout circulating oil into and out of an oil-pumping chamber on oneside thereof and wherein the diaphragm piston assembly is operatedthrough an improved cam driven push rod assembly for producing positivecompressor operation. v

An object'of the present invention is to improve single stage diaphragmpiston type compressors by the provision therein of an open-endedcompressor housing that is adapted to be adjustably mounted with respectto a support pedestal having cam operated means therein so as to varythe length of stroke of a push rod to control clearance volume on theair side of the diaphragm piston thereby to control the maximum staticpressure of the system.

. 2 ing push rod assembly which is spring 'biased interiorly of thedifferential housing into operative engagement with the cam.

The housing includes an opposite open end thereon closed by an improveddry operated piston and diaphragm assembly. More particularly, thediaphragm is supported at one surface thereof by a protector platehaving a peripheral edge for supportingly receiving the diaphragmadjacent a hinge peripheral edge thereon. The protector plate furtherincludes a central connector portion thereon secured to the push rod anda plurality" of circumferentially located rivets thereon eachsupportingly received within a counterbored opening through the pistonand having head portions on the rivet deformed to fill an exposedpumping surface of the piston that is reciprocated by the piston intoand out of a pumping chamber formed in a combination valve plate andcylinder head member. 1 The axial position of the compressor housingwithin the differential housing support fixture will locate the push rodwith respect to the cam so that maximum amount of push rod stroke can bevaried. Axial location of the push rod will cause the peak of the pistonstroke to occur away from the top surface of the pumping chamber so asto increase clearance volume and consequently lower the static pressurecapability of the compressor.

Further objects and advantages of the present invention will be apparentfrom the following description, reference being had to accompanying thedrawings, wherein a'preferred embodiment of the invention is clearlyshown.

' the present invention;

Yet another object of the present invention is to provide an improvedeasily assembled, compact, short stroke diaphragm-piston single-stageair compressor having an open ended housing closed by an improved pistondiaphragm assembly which includes protector plate means for protectingthe diaphragm and for securing a piston for reciprocation by apush rodassembly which extends through one ofthe open ends of the compressorhousing and wherein a combination pumping chamber and valve supportplate is secured to the other open end of the compressor housing to forma pump chamber with the diaphragm piston assembly which can have theclearance volume therein adjusted by axial positioning of the open endof the housing and the push rod operator therein with respect to a drivesupport fixture including cam drive means therein for operating the pushrod of the assembly.

These and other objects of the present invention are attained in oneworking embodiment which has a differential housing with a rotatable camlocated therein for operating the compressor and wherein a supportfixture is formed on the differential housing including an axial boretherein for supportingly receiving an axially positioned extension on anair compressor housing. The extension is open-ended and supports areciprocat- FIG. 2 is an enlarged vertical sectional view taken alongthe section line 2--2 of FIG. 1;

FIG. 3 is a fragmentary sectional view showing a further embodimentofthe present invention;

FIG. 4 is a view in vertical section taken along the line 44 of FIG. 3looking in the direction of the arrows;

and

FIG. 5 is a section along line 5-5 of FIG. 4.

Referring now to FIG. 1, a rear suspension 10 of a vehicle isillustrated including a chassis frame having side members 12, 14 joinedtogether by a cross frame member 16 that overlies an unsprung axlehousing 18.

Primary suspension springs (not shown) have their upper ends supportedon bracket seats 20, 22 on the cross member 16. These springs supportthe chassis frame in sprung suspension on the axle housing 18. Groundengaging wheel assemblies 24, 26 are each driven by an axle 28. The axlein turn is operatively associated with differential gear means within adifferential housing 30 located midway of the axle housing 18. Drive tothe differential housing 30 is through a propeller shaft 32 connected toa differential pinion 34.

A supplemental load supporting air spring device 36 is supported betweena ledge 38 on the differential housing 30 and the cross member 16. It isselectively inflated by air supply from an improved air compressor anddrive assembly 40 constructed in accordance with certain principles ofthe present invention.

The assembly 40 includes a compressor 42 having an inlet fitting 44thereon connected'to a conduit 46 which is communicated with the exhaustfrom the air spring assembly 36 for returning air from the air spring tothe compressor during system operation. The compressor further includesa high pressure discharge fitting 50 connected to a supply conduit 52through which air is supplied to an inlet or inflation port on the airspring assembly 36.

In accordance with certain principles of the present invention, thecompressor and drive assembly 40 is operated only in response to vehicleoperation when the cam pinion 34 is operated to drive'a cam 53 connectedthereto. The cam 53 operates a compressor drive mechanism 54. Thecompressor drive mechanism 54 operates a combination diaphragm andpiston assembly 56 with respect to a valve and pumping chamber assembly58 which includes means for controlling fluid flow into and out ofcompressor 42 so as to produce a continuous flow of compressed air intothe air spring 36 during vehicle operation.

A valve mechanism (not shown) in the air spring assembly 36 is operatedto bleed excess air flow from the air spring 36 during continuous flowof compressed air thereto. The excess air flow is thence discharged andreturned through the inlet conduit 46 to complete a closed loopcontinuous operation.

For purposes of the present invention. the aforedescribed description ofthe system will suffice. For further details ofthe closed loop system ofthis type, reference may be had to copending United States applicationSer. No. 307,378 Filed Nov. 17, 1972, by Robert E. Owen, entitledLeveling System with Center Mounted Air Spring.

One feature of the present invention is the manner in which thecompressor 42 is mounted with respect to the differential housing 30.The differential housing 30 more particularly includes a side mountingflange 60 which has an axial bore 62 therethrough. A tubular extension64 defines one open end on a compressor housing member 66. It issupportingly'received within the bore 62 and is sealed with respectthereto by an O-ring 68 supported in the extension 64 to be located insealing engagement with the surface of bore 62. The extension 64 isaxially positionable within the bore 62 so as to locate the sphericalend 70 of an elongated push rod 72 of the drive mechanism 54 axiallywith respect to the bore 62.so as to be either spaced from or located inengagement with the low point of the cam 53. The compressor shell orhousing 66 is then fixedly secured with respect to the flange 60 bysuitable clamp means to maintain the desired stroke relationship. Bycontrolling the length of stroke of the push rod 72, the piston anddiaphragm assembly 56 is positioned at the end of the stroke so that thepiston will be spaced closer or farther away from the top of a pumpingchamber 74 formed in the combination valve and cylinder head 58. Thepositioning of the peak of the piston stroke with respect to the'pumpingchamber surface will produce a controlled clearance volume whichconstitutes the amount of air remaining in the pumping chamber 74 whenthe piston and diaphragm assembly 56 has reached the peak of its stroke.By spacing the peak of the stroke away rom the top surface of thepumping chamber 74 the clearance volume will be increased to cause acontrolled reduction of the maximum static pressure output of thecompressor. In order to adjust the compressor 40 with respect to the cam53 to control the amount of volumetric efficiency the compressor isforced against the high point of the cam 53 until the diaphragm pistonassembly 56 is in solid contact with an upper surface 76 of the pumpingchamber 74. An axial force 77 is gradually removed from the pumpinstallation and an indicator will establish a calculated pistonposition to maintain a desired clearance volume required to produce agiven static output pressure. At this point, the air compressor isfastened securely in its axial location so as to maintain the desiredclearance volume control.

In the illustrated arrangement, the compressor housing 66 is sealed withrespect to the flange 60 following adjustment by means of a largediameter resilient O- ring 78 seated between the end of flange 60 and ashoulder 79 on housing 66.

The compressor housing 66 includes an inner opened end 80 in which issupportingly received a bearing sleeve 82 elongated to extend outwardlyof end 80. More particularly, the bearing sleeve 82 includes a headportion 84 having the outer periphery thereof supported within the endopening 80. It in turn includes a plurality of circumferentially spacedholes 86 therein. In one working embodiment there are ninecircumferentially spacedholes that provide unrestricted flow of airthrough the end opening 80 to and from an open end 87 on the oppositeend of the housing 66 closed by the piston and diaphragm assembly 56 andlocated to permit suction movement of the assembly 56 with re spect tothe housing 66.

The piston and diaphragm assembly 56 seals the opened end 87 and isconnected to the push rod 72 to be reciprocated thereby into and out ofthe opened end 87 and into and out of the pumping chamber 74 to producea single stage compression of fluid on one side of the assembly 56. v

The assembly 56 more particularly includes a protector plate 88 whichhas a tubular extension 90 centrally formed on one side thereof which isrolled inwardly at 92 to interlock within a groove Men the end of thepush rod 72. Radially outwardly of the central connector 90 the plate 88has a plurality of circumferentially formed rivets integrally locatedthereon each directed through a countersunk opening 96 within a pistondisc 98. Head portions 100 on each of the rivets 94 are de formed so asto form a flat continuously level surface at each of the countersunkopenings 96 which define a continuous uninterrupted surface across thefull planar extent of the front 102 of the piston disc 98.

A flexible diaphragm 104 in the assembly 56 is supported between theprotector plate 88 and the rear surface of the piston-disc 98. It has aradially outwardly located hinged edge 106 thereon held in sealingengagement between an annular flange 108 on the housing 66 and anannular end face 110 formed on the valve and cylinder head 58. The edge106 is secured in sealing relationship therebetween by a sheet metalcover 114 that has a radially inwardly bent edge 116 thereon overlying achamfered surface 118 on the outer surface of the housing 66. It furtherincludes an outer wall portion 120 which is located against an annularouter face 122 of the head 58 where it is sealed by an O-ring 124. Thisdefines a high pressure cavity 126 that is communicated through a tubemember 128 with the high pressure fitting or discharge fitting 50.Within the high pressure chamber 126 is located a discharge valve discI30 having its outer periphery overlying and closing a plurality ofcircumferentially located discharge openings 132. The disc is held inplace by a rivet 134 to seal the discharge openings 132. Upon movementof the piston disc 98 into the pumping chamber 74 fluid is compressedtoact on the valve disc 132 to force it into supported relationship with adeflector plate 136 so as to flow from the pumping chamber 74 throughthe discharge openings 132 thence through the tube 128 and outwardly ofthe discharge conduit 52. This compression stroke is produced byrotation of the high point of the cam 36 against the spherical surface70 on push rod 72. The compression'stroke or return stroke of the pushrod 72 is produced by a return spring 138 which is of conicalconfiguration including a small diameter end 140 thereon supportedagainst a retaining ring 142 on the end of the push rod 72. A' largediameter end 144 of the spring surrounds the bearing sleeve 82 and islocated in engagement with the sleeve head 84 so as to force the pushrod 72 outwardly of the sleeve 82 against the outer surface of the cam53. Thus it serves as a return mechanism for the diaphragm and pistonassembly 56. In the illustrated arrangement, the outer periphery of thepush rod 72 includes a peripheral groove 146 therein that directslubricant from a sump chamber 148 within the housing 30 along thebearing surface of the bearing extension 82 upon opposite reciprocationof the push rod 72 therein.

During the movement of the piston and diaphragm assembly 56 to theright, as produced by the return spring 144, the volume of the pumpingchamber 74 is increased by movement of the piston disc 98 away from theinner surface 76 of chamber 74. This causes a valve suction valve disc150 to move away from suction ports 152 in the valve and cylinder head58. In the illustrated arrangement, a rivet 154 secures the suctionvalve disc 150 in place on the inner surface of the pumping chamber 74.A suction cavity 156 is formed in the outer wall of the head 58 incommunication with the suction openings 152. It is communicated througha tube 158 with the suction fitting 44.

The embodiment illustrated in FIGS. 3 and 4 shows a compressor assemblyfor use in a rear suspension leveling system like that shown in FIGS. 1and 2. The compressor assembly 160 includes a housing shell 162corresponding to the housing 66 in the first embodiment. It carries anannular O-ring 164 for sealing against a support fixture defined by anupstanding support flange or collar 166 on an inclined side surface 168ofa differential housing 170. The housing is fixedly secured in place bymeans of a sleeve 172 and a clamp ring 174. The sleeve 172 includes aplurality of axial slots 176 located circumferentially therearound forgripping the outer surface of the housing 162 so as to hold it axiallyto locate the spherical end 178 of a push rod 180 corresponding to thepush rod 72 in the first embodiment.

In this arrangement, the push rod 180 is biased inwardly by a returnspring 182 against an inclined surface 184 having a plurality of lobesformed thereon of a differential case cam 186. The inclined surface 184is formed generally parallel to the inclined side surface 168 of thedifferential housing.

Side surface 168 is located at one side of the differential housingwhich supportingly receives the inner end 188 of an axle housing 190 foran axle 191. The inner end is secured in place on the differentialhousing 168 by suitable fastening means such as bolts 192. The

inner end 188 of the axle housing 190 is counterbored at 194 tosupportingly receivea shaft bearing assembly 196 which supports abearing surface 198 on the differential case 199 for rotation withrespect to the axle housing 190. The'cam 186 has an annular base portion200 thereon seated on the surface 198, where it is fixedly secured by atang 201 against rotationwith respect to the surface 198. Thearrangement permits inclusion of a compressor operating cam within thedifferential housing 168. without requiring; modification of existingdifferential mechanisms within the housing 168. By virtue of theaforedescribed arrangement, the compressor 160 can be located withrespect to a housing out of the way of operative components thereof andthe location of the cam on the differential case permits an inclinedsurface thereon to be. located parallel to the normal differentialhousing configuration so as to position the end 178 of the push rod 180in a perpendicular relationship to the drive cam surface thereby toreduce side thrust on the push rod.

In the embodiment of FIGS. 3 and 4, the pump has working components likethose shown in FIG. 2. It includes an outer cover 202 which joins avalve head pump chamber to an open ended pump or compressor housing. Inthis arrangement a common header with calibrated pressure relief valveis included. The header is illustrated at 204 and includes a dischargeend 206 and an inlet end 208 thereon. An offset leg 210 includes arelief valve bore 211 having a valve seat 212 with a ball 214 springbiased thereon by a spring 216 which is adjusted to produce apredetermined relief valve calibration on the ball 214 by means of acalibration screw 218 threadably received in bore 211. The valve seat212 is formed between offset passageways 220, 222 which communicate theoutlet port 206 with the inlet port 208 when the predetermined maximumpressure condition within the discharge side of the system moves, theball from the relief valve seat 212 thereby causing the high pressurebuildup to bypass directly back to the suction side of the compressorfor relieving the system.

The detailed description of the preferred embodiment of the inventionfor the purpose of explaining the principles thereof is not to beconsidered as limiting or restricting the invention, sincemany-modifications may be made by the exercise of skill in the art.

What is claimed is as follows:

1. In a fluid compressor and drive assembly, rotatable drive means fordriving said compressor, a housing for said rotatable drive means, saidhousing having an opening therethrough and having cylindrical wall meansfixed to said housing extending from said opening, said compressorcomprising a compressor casing having an enlarged annular head portionand having reduced diameter tubular extensionmounted for slidingtelescopic movement with respect to said cylindrical wall means,fastener means for releasably securing said tubular extension to saidwall means of said housing, piston means mounted for reciprocal movementin said head portion and cooperating therewith to provide an expandableand contractable chamber therein. fluid supply means operativelyconnected to said chamber for supplying fluid thereto in response to theexpansion of said chamber, fluid exhaust means operatively connected tosaid chamber for exhausting fluid therefrom in response to thecontraction of said chamber, piston drive means for stroking said pistonmeans in said head portion to expand and contract said chamber, saidpiston drive means extending longitudinally through said tubularextension of said compressor casing and said opening in said housinginto engagement with said rotatable drive means, support means mountedin said tubular extension, said support means having a cylindrical headportion fitted into said tubular extension of said compressor casingadjacent to said piston means, said support means further having bearingsleeve means radially inwardly of said head portion for slidablysupporting said pistondrive means, elongated helical spring meansoperatively connected between said head portion and said piston drivemeans providing a force for moving said compressor casing linearlyoutwardly with respect to said housing so that said casing can besubsequently fixed at a predetermined station with respect to saidhousing by said fastener means and for maintaining said piston drivemeans in contact with said rotatable drive means.

2. In a fluid compressor and drive assembly, rotatable cam means fordriving said compressor, a housing for i said rotatable cam means, saidhousing having an opening therethrough and cylindrical flange meansextending outwardly from said housing to provide a passage connected tosaid opening, said compressor comprising a casing having an annular headportion with a cavity therein and having a reduced diameter-hollowtubular extension integral with said head portion leading outwardly fromsaid cavity, means supporting said tubular extension for lineartelescoping movement with respect to said cylindrical flange means,fastener means for releasably securing said tubular extension to saidflange means of said housing, diaphragm means mounted for flexingmovement in said cavity of said head portion and cooperating with saidhead portion to provide an expandable and contractable chamber therein,fluid supply means operatively connected to said chamber for supplyingfluid thereto in response to the expansion of said chamber, fluidexhaust means operatively connected to said chamber for exhausting fluidtherefrom in response to the expansion of said chamber, fluid exhaustmeans operatively connected to said chamber for exhausting fluidtherefrom in response to the contraction' of said chamber, reciprocallymovable drive means operatively connected to said diaphragm for flexingsaid diaphragm means in said head portion to expand and contract saidchamber in response to rotationof said cam means, said drive meanscomprising rod means extending longitudinally through said tubularextension and said opening in said housing into engagement with saidrotatable drive means, support means mounted in said tubular extensionfor supporting said rod means between the ends thereof, said supportmeans comprising a head portion mounted in said tubular extension andintegral bearing sleeve means for said rod means supported radiallyinwardly of said head portion, helical spring means disposed around saidbearing sleeve means and operatively positioned between said headportion and one end of said rod means for moving said casing outwardlywith respect to said housing so that said casing can be subsequentlyfixed at a predetermined station with respect to said housing by saidfastener means and for maintaining said rod means in yieldable contactwith said rotatable cam means so that said cam means can flex saiddiaphragm and pump fluid from said fluid chamber into said fluid exhaustmeans.

3. A fluid compressor and drive assembly comprising rotatable cam means,a housing for said rotatable cam means, said housing having an openingtherethrough and cylindrical flange means extending outwardly from saidhousing to provide a passage connected to said opening, said compressorcomprising a casing having a head portion with a cavity therein and ahollow tubular extension leading outwardly from said cavity, supportmeans mounting said tubular extension for longitudinal telescopingmovement on said cylindrical flange means, fastener means for securingsaid tubular exten sion in adjusted position to said flange means ofsaid housing, diaphragm means mounted for flexing movement in said headportion and cooperating therewith to provide an expandable andcontractable chamber therein, fluid supply means operatively connectedto said chamber for supplying fluid thereto in response to the expansionof said chamber, fluid exhaust means operatively connected to saidchamber for exhausting fluid therefrom in response to the contraction ofsaid chamber, reciprocally movable drive means operatively connected tosaid diaphragm for flexing said diaphragm means in said head portion toexpand and contract said chamber in response to rotation of said cammeans, said drive means comprising cylindrical push rod means extendinglongitudinally through said tubular extension and said opening in saidhousing into engagement with said rotatable drive means, support meansmounted in said tubular extension for supporting said rod means, saidsupport means comprising a head portion mounted in said tubularextension and cylindrical bearing sleeve means supported radiallyinwardly of said head portion, said sleeve means extending axiallybeyond said head portion and having an axial opening extendingtherethrough, said push rod extending through said axial opening andhaving a major portion of its length supported by said sleeve means,helical spring means operatively disposed around said bearing sleevemeans, means operatively mounting said spring means between one end ofsaid head portion and one end of said rod means for moving said supportmeans and said casing outwardly with respect to said housing so thatsaid casing can be subsequently fixed at a predetermined station withrespect to said housing by said fastener means and for maintaining saidpush rod means in yieldable contact with said rotatable cam means sothat said cam means can axially move said push rod and flex saiddiaphragm and pump fluid from said fluid chamber into said fluid exhaustmeans.

4. In a fluid compressor and drive assembly, a rotatable input,rotatable cam means operatively connected to said input for driving saidcompressor, a housing for said rotatable cam means, said housing havinga cylindrical extension fixed thereto 'with a passage therethroughleading into the interior of said housing, said compressor comprising acasing having a head portion and a tubular body portion, support meansfor mounting said tubular body portion for linear telescoping movementinto and out of said cylindrical extension, fastener means for securingsaid tubular body in an adjusted position in said extension of saidhousing, piston means mounted for reciprocal movement in said headportion and cooperating therewith to provide an expandable andcontractable chamber therein, fluid supply means operatively connectedto said chamber for supplying fluid thereto in response to the expansionof said chamber, fluid exhaust means operatively connected to saidchamber for exhausting fluid therefrom in response to the contraction ofsaid chamber, push rod means for stroking said piston means in said headportion to expand and contract said chamber, said push rod meansextending longitudinally through said extension into engagement withsaid rotatable cam means, support means mounting said push rod means forlimited axial movement in said tubular body portion, said support meanscomprising a head portion fitted within said cylindrical extension and aconcentric bearing sleeve for said push rod means, helical spring meansin said body portion and operatively mounted between said head portionand said push rod means for moving ment of said cam means.

1. In a fluid compressor and drive assembly, rotatable drive means for driving said compressor, a housing for said rotatable drive means, said housing having an opening therethrough and having cylindrical wall means fixed to said housing extending from said opening, said compressor comprising a compressor casing having an enlarged annular head portion and having reduced diameter tubular extension mounted for sliding telescopic movement with respect to said cylindrical wall means, fastener means for releasably securing said tubular extension to said wall means of said housing, piston means mounted for reciprocal movement in said head portion and cooperating therewith to provide an expandable and contractable chamber therein, fluid supply means operatively connected to said chamber for supplying fluid thereto in response to the expansion of said chamber, fluid exhaust means operatively connected to said chamber for exhausting fluid therefrom in response to the contraction of said chamber, piston drive means for stroking said piston means in said head portion to expand and contract said chamber, said piston drive means extending longitudinally through said tubular extension of said compressor casing and said opening in said housing into engagement with said rotatable drive means, support means mounted in said tubular extension, said support means having a cylindrical head portion fitted into said tubular extension of said compressor casing adjacent to said piston means, said support means further having bearing sleeve means radially inwardly of said head portion for slidably supporting said piston drive means, elongated helical spring means operatively connected between said head portion and said piston drive means providing a force for moving said compressor casing linearly outwardly with respect to said housing so that said casing can be subsequently fixed at a predetermined station with respect to said housing by said fastener means and for maintaining said piston drive means in contact with said rotatable drive means.
 2. In a fluid compressor and drive assembly, rotatable cam means for driving said compressor, a housing for said rotatable cam means, said housing having an opening therethrough and cylindrical flange means extending outwardly from said housing to provide a passage connected to said opening, said compressor comprising a casing having an annular head portion with a cavity therein and having a reduced diameter hollow tubular extension integral with said head portion leading outwardly from said cavity, means supporting said tubular extension for linear telescoping movement with respect to said cylindrical flange means, fastener means for releasably securing said tubular extension to said flange means of said housing, diaphragm means mounted for flexing movement in said cavity of said head portion and cooperating with said head portion to provide an expandable and contractable chamber therein, fluid supply means operatively connected to said chamber for supplying fluid thereto in response to the expansion of said chamber, fluid exhaust means operatively connected to said chamber for exhausting fluid therefrom in response to the expansion of Said chamber, fluid exhaust means operatively connected to said chamber for exhausting fluid therefrom in response to the contraction of said chamber, reciprocally movable drive means operatively connected to said diaphragm for flexing said diaphragm means in said head portion to expand and contract said chamber in response to rotation of said cam means, said drive means comprising rod means extending longitudinally through said tubular extension and said opening in said housing into engagement with said rotatable drive means, support means mounted in said tubular extension for supporting said rod means between the ends thereof, said support means comprising a head portion mounted in said tubular extension and integral bearing sleeve means for said rod means supported radially inwardly of said head portion, helical spring means disposed around said bearing sleeve means and operatively positioned between said head portion and one end of said rod means for moving said casing outwardly with respect to said housing so that said casing can be subsequently fixed at a predetermined station with respect to said housing by said fastener means and for maintaining said rod means in yieldable contact with said rotatable cam means so that said cam means can flex said diaphragm and pump fluid from said fluid chamber into said fluid exhaust means.
 3. A fluid compressor and drive assembly comprising rotatable cam means, a housing for said rotatable cam means, said housing having an opening therethrough and cylindrical flange means extending outwardly from said housing to provide a passage connected to said opening, said compressor comprising a casing having a head portion with a cavity therein and a hollow tubular extension leading outwardly from said cavity, support means mounting said tubular extension for longitudinal telescoping movement on said cylindrical flange means, fastener means for securing said tubular extension in adjusted position to said flange means of said housing, diaphragm means mounted for flexing movement in said head portion and cooperating therewith to provide an expandable and contractable chamber therein, fluid supply means operatively connected to said chamber for supplying fluid thereto in response to the expansion of said chamber, fluid exhaust means operatively connected to said chamber for exhausting fluid therefrom in response to the contraction of said chamber, reciprocally movable drive means operatively connected to said diaphragm for flexing said diaphragm means in said head portion to expand and contract said chamber in response to rotation of said cam means, said drive means comprising cylindrical push rod means extending longitudinally through said tubular extension and said opening in said housing into engagement with said rotatable drive means, support means mounted in said tubular extension for supporting said rod means, said support means comprising a head portion mounted in said tubular extension and cylindrical bearing sleeve means supported radially inwardly of said head portion, said sleeve means extending axially beyond said head portion and having an axial opening extending therethrough, said push rod extending through said axial opening and having a major portion of its length supported by said sleeve means, helical spring means operatively disposed around said bearing sleeve means, means operatively mounting said spring means between one end of said head portion and one end of said rod means for moving said support means and said casing outwardly with respect to said housing so that said casing can be subsequently fixed at a predetermined station with respect to said housing by said fastener means and for maintaining said push rod means in yieldable contact with said rotatable cam means so that said cam means can axially move said push rod and flex said diaphragm and pump fluid from said fluid chamber into said fluid exhaust means.
 4. In a fluid compressor and drive assembly, a rotatable input, rotatable cam means operatively connected to saId input for driving said compressor, a housing for said rotatable cam means, said housing having a cylindrical extension fixed thereto with a passage therethrough leading into the interior of said housing, said compressor comprising a casing having a head portion and a tubular body portion, support means for mounting said tubular body portion for linear telescoping movement into and out of said cylindrical extension, fastener means for securing said tubular body in an adjusted position in said extension of said housing, piston means mounted for reciprocal movement in said head portion and cooperating therewith to provide an expandable and contractable chamber therein, fluid supply means operatively connected to said chamber for supplying fluid thereto in response to the expansion of said chamber, fluid exhaust means operatively connected to said chamber for exhausting fluid therefrom in response to the contraction of said chamber, push rod means for stroking said piston means in said head portion to expand and contract said chamber, said push rod means extending longitudinally through said extension into engagement with said rotatable cam means, support means mounting said push rod means for limited axial movement in said tubular body portion, said support means comprising a head portion fitted within said cylindrical extension and a concentric bearing sleeve for said push rod means, helical spring means in said body portion and operatively mounted between said head portion and said push rod means for moving said casing outwardly with respect to said cylindrical extension so that said casing can be subsequently fixed at a predetermined station with respect to said housing by said fastener means and for maintaining said push rod means in contact with said rotatable cam means so that said cam means can stroke said piston means outwardly to contract said chamber on predetermined rotational movement of said cam means and so that said spring means can stroke said piston means inwardly in response to further predetermined rotational movement of said cam means. 